cr500 motor in yz250 frame? yz500af?

[c00kiebr0s]

i really like my yz250, way it looks, feels, handles and how easy its is to work on. but i need a 500 2t. has anyone put a cr500 motor in a yz250 2t frame? 

now before any says how silly using a yz 2t frame is here are my reasons

All the aftermarket parts already on the bike

allready had the yz suspension setup with springs valves and everything else which was over $1k

and have i mentioned how much i love the yz platform?

if buy a cr500 motor and sell my old one it wont cost too much

[markmc2]

Y not add 295 jug to your engine?

[subxero]

it's been done before, and besides, where there is a will there is a way.... and deep pockets or your personal machine shop don't hurt.  I don't know anything about it though.   Obvious things to consider are swingarm pivot spindle diameter,  distance between inner swingarm pivot and engine pivot mount, sprocket/chain alignment and will the head clear/fit with pipe ect...   

My opinion, if you like to fab and make crap work then go for it, otherwise stick with tried and trued.  Could buy an already built Honda AF for like $4k here in the US then do a SSS mod or something.    There is a cherry KX500 AF for sale near me,   if i had a use for it and the $ i would be all over it.  

[Motox367]

Dont ever see any of those its single spar frame barely enough room for the 25o engine.  But ya id definitely have one of them  would be a serious weapon 

[CaptDan]

Something like this?

http://www.performanceforums.com/forums/showthread.php?67289511-YZ-CR500-Fi-efi-2-stroke!

[Motox367]

1 minute ago, CaptDan said:

Something like this?

http://www.performanceforums.com/forums/showthread.php?67289511-YZ-CR500-Fi-efi-2-stroke!

I remember seeing that couple years ago its badass for sure.  That thing is seriously fast. But that's mot a YZ250 chassis 

[speedtoad]

Bigger heavier motor, suspension, handling, and frame will all be affected.
Bad idea.

[markmc2]

i'd big bore that yz and if it doesn't have enough power for you pickup a nice honda 500 for $3500 on craigslist.

[Kinger317]

Just by the '19 from Yamaha when it comes out.

[SteveThe Snakes]

Used AF CR500's can be had for a good price. Doing it on a Yamaha frame that doesn't have easy weld up kits available and has already been done results in big $$$. 

[c00kiebr0s]

For every one saying buy a cr500af i would but i live in australia and they cost around $10k and about $8k for a standard cr500. I could get one shipped over but ocne ived paid for currency conversion, shipping and import tax i wouldnt have saved any money. Also a 300 kit wouldnt do it, not gonna happen. An esr 345 kit with lots of mods might be close but as every one knows there no replacement for displacement and a 500 2t is something else. 

[Motox367]

3 minutes ago, c00kiebr0s said:

For every one saying buy a cr500af i would but i live in australia and they cost around $10k and about $8k for a standard cr500. I could get one shipped over but ocne ived paid for currency conversion, shipping and import tax i wouldnt have saved any money. Also a 300 kit wouldnt do it, not gonna happen. An esr 345 kit with lots of mods might be close but as every one knows there no replacement for displacement and a 500 2t is something else. 

Just get a 450 then . I prefer 250 over any bigbore kit more racey 

[c00kiebr0s]

1 hour ago, Motox367 said:

Just get a 450 then . I prefer 250 over any bigbore kit more racey 

I have a 2010 crf450r, i hate it. 

[Motox367]

1 minute ago, c00kiebr0s said:

I have a 2010 crf450r, i hate it. 

Id hate that too lol 

[c00kiebr0s]

Just now, Motox367 said:

Id hate that too lol 

I only keep it cause my dad rides it. Ive ridden a yz450 2013 model and i hate that too. Just not a 4t person. 

[Motox367]

4 minutes ago, c00kiebr0s said:

I only keep it cause my dad rides it. Ive ridden a yz450 2013 model and i hate that too. Just not a 4t person. 

Different strokes for different folks 

[BoxcarWilly]

Waste of time and money. Just buy a steel frame CR500 and have the suspension set up well. 

[c00kiebr0s]

Just now, BoxcarWilly said:

Waste of time and money. Just buy a steel frame CR500 and have the suspension set up well. 

Waste of time maybe for some people but i think it will be worth it, waste of money certainly not it would be about $6k cheaper. I plan to just buy the 500 motor not the whole bike. 

[BoxcarWilly]

2 minutes ago, c00kiebr0s said:

Waste of time maybe for some people but i think it will be worth it, waste of money certainly not it would be about $6k cheaper. I plan to just buy the 500 motor not the whole bike. 

You'll spend more money (time is money) getting the motor to fit properly in the frame than you would to just buy a bike with the frame and suspension already designed for that motor. Not to mention you'll ruin a perfectly good YZ250 chassis. The suspension and ergonomics of the frame are not built for that motor and the chances of it actually working and handling well are slim to none. 

 

[BoxcarWilly]

Not to mention all of that $1000 you just spent on suspension modification will be thrown out the window.